Commit Gemfile.lock for reproducible tests

[kpumuk]

Addressed a syntax error in the thrift.gemspec, and committed Gemfile.lock files for both the gem and tests. Gems source switched to https://rubygems.org (from http://).

This is a strongly recommended approach according to the Bundler team:

As a result, you SHOULD check your Gemfile.lock into version control, in both applications and gems. If you do not, every machine that checks out your repository (including your production server) will resolve all dependencies again, which will result in different versions of third-party code being used if any of the gems in the Gemfile(5) or any of their dependencies have been updated.
https://bundler.io/man/bundle-install.1.html#THE-GEMFILE-LOCK

Also helps with Dependabot, which will be able to bump the lock file, while we can relax version requirements in the gemspec.

• Did you create an Apache Jira ticket? (Request account here, not required for trivial changes)
• If a ticket exists: Does your pull request title follow the pattern "THRIFT-NNNN: describe my issue"?
• Did you squash your changes to a single commit? (not required, but preferred)
• Did you do your best to avoid breaking changes? If one was needed, did you label the Jira ticket with "Breaking-Change"?
• If your change does not involve any code, include [skip ci] anywhere in the commit message to free up build resources.